Over one-half of the newly diagnosed breast cancers in the United States occur in women 65 years or older. Despite the high prevalence of breast cancer in the elderly, there is a paucity of data regarding the age-associated aspects of this malignancy. The Cancer and Leukemia Group B proposes a comprehensive project to study breast cancer in elderly women. This project includes an adjuvant chemotherapy treatment trial with companion projects to evaluate the impact of treatment regimens on patients' quality of life; to assess patients' adherence to an oral medication; and to study tumor biology and correlations with treatment outcome. The proposed adjuvant chemotherapy trial will compare standard chemotherapy with capecitabine in elderly women with high risk, early stage breast cancer. The objectives of this treatment trial are to compare the efficacy and tolerability of standard chemotherapy versus single agent capecitabine with the primary endpoint being disease-free survival. A total of 720 women aged 65 years or older will enroll in this trial over a period of four years. The quality of life companion will utilize several standardized measures to assess physical, cognitive, social and vocational functioning in patients during and following adjuvant therapy. This quality of life companion will include 175 patients from each study arm. The second companion study will assess the adherence of 175 patients receiving oral capecitabine using an electronic monitoring device. The tumor biology companion study will be submitted under a separate grant application from the University of North Carolina. This study will involve examination of tissue blocks from the primary tumor collected prospectively from all patients enrolled in the adjuvant trial. Biologic characteristics of the tumor will be examined and correlated with treatment outcome. This well integrated project provides a multidisciplinary approach that will address many issues relevant to the treatment of elderly women with breast cancer.